Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The recognition of phosphate and sulphate esters of tyrosine residues has been studied employing antisera with specificity for tyrosine phosphate, and the enzymes aryl sulphatase, and acid and alkaline phosphatases. The ability of tyrosine phosphate, and of phosphate esters of phenol, to inhibit the antiserum was pH dependent. The capacity to effect inhibition appeared to correlate with alterations in the ionisation of the inhibitor. Moreover, the antisera with reactivity for tyrosine phosphate had no reactivity with tyrosine sulphate or sulphate esters of phenol at any pH value studied. The enzymes alkaline phosphatase, acid phosphatase, and aryl sulphatase were also studied. The phosphatases were found not to hydrolyse sulphate ester containing substrate analogues at any pH value in the range 5.0-9.0. In contrast, aryl sulphatase appeared to hydrolyse phosphate esters at pH 5.0 and 7.0, but not at pH 9.0.
...
PMID:Immunochemical recognition of phosphate ester derivatives of phenol rings is dependent upon the electronic charge of the ester group. 242 60

Seven Tyr-protein phosphatase activities were isolated from bovine brain using phosphotyrosyl-casein as a model substrate. The activities were resolved from the cytosolic fraction by a three-step procedure employing successive DEAE-cellulose, phosphocellulose, and gel permeation chromatography steps. The seven activities accounted for 70% of the Tyr-protein phosphatase activity in bovine brain extracts and were distinct from type 1 and type 2 Ser/Thr-protein phosphatases and from the major alkaline phosphatase activities. Apparent molecular weights of the activities by gel permeation chromatography were: phosphotyrosyl-protein phosphatase (PTP)-1A (Mr 86,000), PTP-1B (Mr 24,000), PTP-2 (Mr 88,000), PTP-3 (Mr 90,000), PTP-4 (Mr 80,000), PTP-5 (Mr 48,000), and PTP-6 (Mr 104,000). PTP-5 was the major activity accounting for 26% of total while the remaining activity was divided rather evenly among the other six activities. PTP-5 was further purified to near homogeneity by additional chromatographies on Affi-Gel Blue, heparin-agarose, and Mono S giving an overall purification of 50,000-fold and a yield of 5.8%. One of two major polypeptides (Mr 46,000) in the preparation was identified as PTP-5 since it alone expressed protein phosphatase activity when protein-staining bands were eluted from sodium dodecyl sulfate-polyacrylamide gels and renatured. PTP-5 had a neutral pH optimum, and using phosphotyrosyl-casein as substrate it had a Km of 130 nM and a Vmax of 10 mumol Pi released.min-1.mg protein-1. These kinetic parameters are well within the range of values obtained for other pure protein phosphatases. PTP-5 also dephosphorylated pp60v-src (autophosphorylated at Tyr-416) at 10% of the rate observed with phosphotyrosyl-casein. Additionally the ratio of phosphotyrosyl-casein/pp60v-src phosphatase activity was relatively constant throughout the PTP-5 purification procedure. These results indicate that PTP-5 is able to bind and efficiently dephosphorylate phosphotyrosyl-proteins and suggest that it is a physiologically relevant Tyr-protein phosphatase.
...
PMID:Phosphotyrosyl-protein phosphatases. I. Separation of multiple forms from bovine brain and purification of the major form to near homogeneity. 246 73

The effects of butyrate-mediated differentiation of human colon carcinoma cells on the expression of src-related tyrosine protein kinases were analyzed. The results demonstrate that treatment of a variety of colon carcinoma cell lines with 2 mM sodium butyrate resulted in diminished population doubling rates, altered morphology, decreased anchorage-independent growth, and increased expression of colon epithelial differentiation marker enzymes such as alkaline phosphatase. In butyrate-treated cells, significantly diminished protein kinase activities and abundance of pp60c-src and p56lck were found to parallel the butyrate-induced phenotypic alterations. For the lck gene, the decreased levels in p56lck abundance were found to coincide with diminished levels of steady-state lck mRNAs. In contrast, treatments which arrested the growth of the colon carcinoma cells without inducing differentiation had no effect on the level of expression of these proteins. Furthermore, colon carcinoma cell lines which were found to be resistant to butyrate-induced differentiation showed no change in the kinase activity or abundance of either protein following butyrate treatment. These results indicate that the expression of several src-related kinases in human colon carcinoma can be influenced by the differentiation state of the cells.
...
PMID:Alterations in the expression of pp60c-src and p56lck associated with butyrate-induced differentiation of human colon carcinoma cells. 247 6

Treatment of L-tyrosine in a peroxidase/H2O2 system results in the formation of dityrosine. However, the phosphoester derivative of tyrosine, O-phospho-L-tyrosine, was unable to form dityrosine even in mixtures with free L-tyrosine. Dephosphorylation of O-phospho-L-tyrosine by alkaline phosphatase followed by horseradish peroxidase/H2O2 treatment resulted in the formation of dityrosine. Our in vitro results indicate that phosphorylation/dephosphorylation of L-tyrosine may regulate dityrosine formation, and is supposed to play an important role in protein-protein interactions, i.e. cross-linking.
...
PMID:Phosphorylation of tyrosine prevents dityrosine formation in vitro. 247 82

Binding of epidermal growth factor (EGF) stimulates tyrosyl protein kinase activity of its receptor in the epidermis. This tyrosine residue phosphorylation is thought to be one mechanism by which EGF mediates its effects such as growth stimulation. To modulate a cellular response to EGF, an enzyme which dephosphorylates phosphotyrosyl residues should be present to oppose the effect of the tyrosyl kinase activity of the EGF receptor. We have identified an enzyme in the neonatal mouse epidermis which has the ability to dephosphorylate tyrosyl residues in vitro on EGF receptors. This phosphatase is a soluble protein with a molecular weight greater than 10,000 daltons and shows optimum activity at neutral pH. This epidermal tyrosyl protein phosphatase is not inhibited by tartrate, ATP, and micromolar levels of zinc, but is inhibited by millimolar levels of zinc, magnesium, manganese, and fluoride. Unlike other well-known phosphotyrosyl phosphatases, alkaline phosphatase, and calcineurin, this enzyme is not inhibited by EDTA. Thus, we have identified and partially characterized a possibly unique phosphotyrosyl phosphatase from the epidermis.
...
PMID:Identification of a phosphotyrosyl-protein phosphatase in mouse epidermis. 253 66

Legionella pneumophila infection of guinea-pigs by the aerosol route with either of two strains, one (serogroup I) giving an acute the other (serogroup 3) giving a protracted illness, induced a pyrexia and similar pneumonic lesions. With both strains there was a bacteraemia with early decreases in serum iron and zinc and increases in serum copper concentrations. Marked changes in other serum components were evident only in those animals which had protracted illness (serogroup 3-infected animals). These included transient increases in aminotransferase, creatine kinase and sorbitol dehydrogenase activities and triglyceride levels, together with gradual decreases in alkaline phosphatase and leucine aminopeptidase activities. Serum lysozyme activity and acute-phase protein synthesis increased, as did the ratio of phenylalanine to tyrosine. The findings confirm the relevance of the aerosol-infected guinea-pig model for the investigation of the disease processes and evaluation of therapeutic measures for use in man.
...
PMID:Clinical chemical responses to experimental airborne legionellosis in the guinea-pig. 258 May 46

1. The carbohydrate content of isozyme K of alkaline phosphatase (EC 3.1.3.1) from harp seal intestinal mucosa was examined. The presence of N-acetylglucosamine, N-acetylgalactosamine and considerable amounts of mannose residues was shown. 2. The amino acid content of seal alkaline phosphatase was determined. A high extent of homology (85%) between bovine and seal alkaline phosphatases was demonstrated. 3. By chemical modification lysine, dicarboxylic acids, arginine and tyrosine residues of tetrameric seal alkaline phosphatase are located near or at the active site. By contrast, the modification of either thiol or imidazole groups resulted in no alterations of the enzyme activity. 4. It has been demonstrated that inorganic phosphate is an inhibitor of alkaline phosphatase and entirely prevents the enzyme inactivation with succinic anhydride.
...
PMID:Chemical modification and composition of tetrameric isozyme K of alkaline phosphatase from harp seal intestinal mucosa. 270 30

Surface enhanced Raman scattering (SERS) of some enzymes (alkaline phosphatase, horseradish peroxidase and lactoperoxidase) and some amino acids (tryptophan, tyrosine and phenylalanine) on silver electrodes has been studied. The spectral band intensities of certain amino acids and amino acid residues were determined by their orientation on the surface and depended on the electrode potential (E).
...
PMID:Structure-potential dependence of adsorbed enzymes and amino acids revealed by the surface enhanced Raman effect. 275 91

The dephosphorylation of phospho-amino acids with alkaline phosphatase (AlPase) from calf intestine or Escherichia coli and the phosphorylation of bovine serum albumin (BSA) with epidermal growth factor (EGF) receptor kinase from human A431 epidermoid carcinoma cells were investigated by 31P NMR spectroscopy. The initial rates of the dephosphorylation of phospho-tyrosine (P-Tyr) and phosphoserine (P-Ser) with AlPase were essentially the same in the one-substrate system. In the two-substrate system (P-Tyr plus P-Ser), however, the ratio of the initial rate for P-Tyr vs. P-Ser was 2.4 to 4.5 depending on the buffer and pH conditions employed. This substantiates for the first time the specificity of AlPases to P-Tyr over P-Ser at the free amino acid level. In the stationary phase of the overall process, the dephosphorylation of P-Ser became slow compared to that of P-Tyr in the one-substrate system. The decrease in the rate for P-Ser was further pronounced in the two-substrate system. For this remarkable effect, the rephosphorylation of serine was responsible, as demonstrated in the reaction mixture containing serine, Pi, and AlPase. BSA phosphorylated by EGF receptor kinase exhibited sharp 31P resonances around 0 ppm at neutral pH, far distant from the peak positions (4.9 ppm) of histone H1 phosphorylated by cAMP-dependent protein kinase. These NMR data are directed evidence that BSA was phosphorylated exclusively at the tyrosyl residues, whereas the phosphorylation of histone H1 was at the seryl residues.
...
PMID:Tyrosine-specific dephosphorylation-phosphorylation with alkaline phosphatases and epidermal growth factor receptor kinase as evidenced by 31P NMR spectroscopy. 282 Sep 50

Synthetic peptide 1142-1153 of the insulin receptor was phosphorylated on tyrosine by the insulin receptor and found to be a potent substrate for dephosphorylation by rat liver particulate and soluble phosphotyrosyl protein phosphatases. Apparent Km values were approximately 5 microM. Vm values (nmol phosphate removed/min per mg protein) were 0.62 (particulate) and 0.2 (soluble). This corresponds to 80% of total activity being membrane-associated, indicating that membrane-bound phosphatases are important receptor phosphatases. The phosphatase activities were distinct from acid and alkaline phosphatase. In conclusion peptide 1142-1153 provides a useful tool for the further study and characterization of phosphotyrosyl protein phosphatases.
...
PMID:Assay of phosphotyrosyl protein phosphatase using synthetic peptide 1142-1153 of the insulin receptor. 284 84


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---